<template>
  <div class="box">
    <h4>sonA</h4>
    <el-button @click="test">发射</el-button>
  </div>
</template>

<script>
export default {
  methods: {
    test() {
      this.$bbb.$emit('show', Date.now())
    }
  }
}
</script>

<style lang="scss" scoped>
.box {
  width: 300px;
  height: 300px;
  border: 10px solid red;
}
</style>
